The day I stop believing I can win is the day I'll stop playing tennis.

"You got to put the past behind you before you can move on." And I think that's what my running was all about.

The more you know yourself, the more patience you have for what you see in others.

I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them.

We recognized early on that smart people do very dumb things, and we wanted to know why and who, so that we could avoid them.

Success is not about making money; it's about making a difference.